[amsat-bb] Announcing EO-79 transponder testing for one full orbit

Wouter Weggelaar wouterweg at gmail.com
Tue May 5 09:34:50 UTC 2015

Hi All,

Thank you for sending in your reports and observations. We are one step
closer to comissioning this transponder.

ISIS engineers are busy downloading Whole Orbit Data files of the
activation, but will have to do this on top of their normal work.
Preliminary analysis shows that the power budget is close to calculated but
there is insufficient data at the moment to make conclusions.

We can at this time not be sure when the next activation will be, and when
permanent activation may be considered. If there is more information
available, I will update the BB on this.

>From the reports we can conclude that the current ADCS mode the satellite
is in may provide some signal fading challenges. It also looks like the
frequency is off-nominal. Lastly, we observe that the signal passband has a
different shape than pre-launch. The transponder is definetely workable,
but we would need more time to establish the frequency relation and
passband shape.

Thanks again, best 73s

Wouter PA3WEG

On Mon, May 4, 2015 at 10:37 AM, Wouter Weggelaar <wouterweg at gmail.com>

> Transponder activated at 0830UTC for 95 minutes.
> Wouter PA3WEG
> On Sun, May 3, 2015 at 8:52 PM, Wouter Weggelaar <wouterweg at gmail.com>
> wrote:
>> Hi All,
>> I can hereby confirm Tomorrows intended activation of the AMSAT-NL
>> FUNcube-3 transponder on QB50p1 / EO-79.
>> Date and time:Monday 4th of May, activation around 0830 UTC for one orbit.
>> TLEs are in the normal repositories, COSPAR 2014-033-R, Object# 40025
>> We would like people to try the following frequencies if possible:
>> DOWNLINK: 145.960 USB
>> UPLINK: Tune to match downlink +/- 435.065 LSB
>> The transponder is linear inverting, nominally 30kHz wide, and approx.
>> 500mW output.
>> Also, If you find the transponder busy on those frequencies, feel free to
>> move around and use the entire transponder passband.
>> The passband seems to have a "dip" in the middle which is bigger than
>> expected, but we do welcome feedback about the usability. Also, please
>> limit your uplink power, as it looks like this transponder is as sensitive
>> as FUNcube-1. The spacecraft antenna is a monopole, so we would also be
>> interested in signal fading reports.
>> The comissioning of the transponder done to date is very limited, three
>> activations for 5, 10 and 8 minutes respectively. So your reports are
>> greatly appreciated.
>> We do understand this is a very short notice, but hope that some of you
>> will be able to participate.
>> This was a take-it-or-leave-it opportunity offered by the ISIS engineers
>> for our consideration, and we are again very grateful to ISIS and VKI to
>> give us this opportunity.
>> Wouter PA3WEG
>> FUNcube team
>> On Sun, May 3, 2015 at 12:28 AM, Wouter Weggelaar <wouterweg at gmail.com>
>> wrote:
>>> Dear all,
>>> I would like to inform you all that tomorrow, Monday 4th of may, there
>>> is a fairly high chance we will be allowed to test the AMSAT-NL transponder
>>> for one full orbit.
>>> Details will be made available on short notice, but we are aiming for an
>>> activation starting at ~08:30 UTC and lasting until ~10:10 UTC.
>>> The aim is to characterize the power budget on board EO-79. So we
>>> encourage the usage of this new transponder. Please also report the QSOs
>>> and signal reports to pa3weg at amsat.org
>>> Wouter PA3WEG

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